Soil Profile Characteristics And Their Environmental Significance In "Great Ear" Area Of Lop Nur

Focused on the salt crust compositions, this paper studied the soil profiles in"Great Ear"area of Lop Nur, including the description of profiles, salt mineral composition, comparison of the profiles in different rings, for revealing it's evolution. The major conclusions are as follows:1. The profiles in white ring could be generally grouped into three sedimentary layers, viz. extremely hard salt crust layer, mud–salt mixed layer, and silt layer from top-down. Such sedimentary characteristics indicated that during the evolutionary process Lop Nur experienced three stages of fresh lake–salt lake–dry salt lake.2. The profiles in black ring were comprised of salt crust layer, mud-salt mixed layer, salt crystallized layer, and silt layer, which indicated that Lop Nur gradually experienced slightly brackish lake, brackish lake, salt lake, and dry salt lake.3. Although there are some differences between the profiles of white and black rings, certainly they are very similar. These sedimentary characteristics indicate a successive dry climatic process in the area, while frequent alternative appearance of mud and salt layers in both profiles showing that multiple fluctuations between the dry and wet climates during its evolution.